中文摘要：

采用喷雾干燥法制备出中孔炭微球（MCMSs）,进一步通过液相浸渍得到磁性Fe3O4/MCMSs纳米复合材料,系统研究了复合材料的形貌结构和吸波性能。结果发现,Fe3O4/MCMSs复合材料具有优异的流动性和低密度（0.24~0.33 g/cm3）特征,其中Fe3O4纳米颗粒高度分散在MCMSs中孔孔道内。复合材料具有较高的比表面积（548~735 m2/g）,可以促进多种介电弛豫的形成。在2~18 GHz范围内,复合材料以介电损耗为主,在12.6 GHz处具有最大反射率–25 d B,小于–10 d B的带宽达4.7 GHz。复合材料优异的吸波性能可以归因于均相分布的Fe3O4纳米颗粒和中孔炭微球的协同作用,在增大界面弛豫和电磁波散射的同时,改善了阻抗匹配,减少了电磁波在吸波层表面的反射。

英文摘要：

Fe3 O4/mesoporous carbon microspheres（MCMSs） composites were prepared by a facile wet-impregnation method using spray-drying produced MCMSs as carbon substrates. The structure, morphology and microwave absorbing performance were investigated. Results indicate that the composites have good fluidity and low bulk density of 0.24-0.33 g/m~3. The Fe3 O4 nanoparticles are homogeneously dispersed in the mesoporous channels without blocking the porosity of MCMSs. The resulting Fe3 O4/MCMSs composites have very high BET surface areas of 548-735 m~2/g, which promote multiple relaxations. In the frequency range of 2-18 GHz, the microwave loss is primarily derived from dielectric loss. The composite with 40 wt% Fe3 O4 exhibits a maximum reflection loss of –25 d B at 12.6 GHz and a broad absorption band over 4.7 GHz. Such good microwave electromagnetic performances can be ascribed to the synergistic effects of highly dispersed Fe3 O4 nanoparticles and mesoporous channels, which can increase interfacial relaxation and microwave diffraction as well as reduce the reflection of microwave at the interface between air and absorber.